A cutting positioning method of a filler metal foil tape for a vacuum brazing process

Abstract

The application provides a cutting and positioning method of a filler metal foil strip using a vacuum brazing process, comprising the following steps: step 1: image recognition is performed on a core of a dot matrix sandwich structure to generate a core surface contour two-dimensional image, including image acquisition, image rapid processing and contour recognition; step 2: the core contour parameters generated in step 1 are introduced into a control system, and superfast laser processing technology is used to realize precise and nondestructive cutting of the filler metal foil strip, so that excessive heat input is avoided to affect the microstructure of the filler metal strip; step 3: the amorphous filler metal foil strip prepared in step 2 is laid according to process requirements, multiple layers of the amorphous filler metal strip are laid to form a complex variable-thickness filler metal foil strip; and a micro-resistance spot welding process is used to connect the complex variable-thickness filler metal foil strip and a dot matrix sandwich panel, so that precise positioning of the filler metal foil strip is realized. Through precise cutting and positioning of the filler metal foil strip, the application can reduce filler metal weight gain while ensuring welding quality, and meet the light weight requirement.

Description

Technical Field

[0001] This invention relates to the field of brazing foil processing technology, and in particular to a method for cutting and positioning brazing foil using a vacuum brazing process. Background Technology

[0002] A lattice sandwich structure is a network-like geometric structure composed of a series of individual elements connected by joints. It is named for its ordered and regular microstructure, which resembles the configuration of a microcrystalline lattice. Its constituent elements primarily bear axial loads, and the structural load-bearing efficiency can be improved by distributing material among locally discrete elements. Common lattice sandwich structures include two-dimensional periodic lattice structures represented by honeycomb and corrugated structures, and three-dimensional periodic lattice structures represented by pyramid and tetrahedral structures. Due to the high specific strength and specific stiffness of lattice sandwich structures, multifunctional properties such as energy absorption, heat insulation, and sound insulation can be achieved by changing the interlayer filling material. This structure is widely used in aerospace, automotive, and shipbuilding industries.

[0003] Lattice sandwich structures typically consist of a lattice core and its upper and lower panels. Depending on the application and conditions, the core structure may include corrugated, honeycomb, or pyramidal structures, while the panel / core materials may include aluminum alloys, titanium alloys, or high-temperature alloys. Common connection methods between the core and panels include vacuum brazing, adhesive bonding, and resistance spot welding. In vacuum brazing, lattice sandwich structures often employ a method where the upper and lower panels are completely covered with amorphous foil solder strips, with the entire solder strip embedded between the core and the panel. For lattice sandwich structures with a thickness of 1mm or more, the solder strip adds less than 2% to the weight. However, with increasing demands for lightweighting, the panels of lattice sandwich structures are being thinned to 0.1–0.5mm, resulting in a 20% weight increase for the solder strips. This makes the entire solder strip unsuitable for the extreme lightweight requirements of lattice sandwich structures. Furthermore, in the vacuum brazing process, only the brazing filler metal in the lattice core wall region plays a metallurgical bonding role. The remaining brazing filler metal not only fails to have a beneficial effect on the formation of the welded joint, but also causes a significant erosion effect, reducing the joint strength and mechanical properties of the panel, thereby affecting the various properties of the lattice sandwich structure. Summary of the Invention

[0004] To address the above problems, this invention provides a method for cutting and positioning brazing foil strips using a vacuum brazing process.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for cutting and positioning brazing foil strips using vacuum brazing technology includes the following steps:

[0007] Step 1: Perform image recognition on the core of the lattice sandwich structure to generate a two-dimensional image of the core surface contour, including image acquisition, fast image processing, and contour recognition;

[0008] Step 2: Import the core contour parameters generated in Step 1 into the control system, and use ultrafast laser processing technology to achieve precise and non-destructive cutting of the brazing foil strip, avoiding excessive heat input from affecting the microstructure of the brazing foil strip;

[0009] Step 3: The amorphous brazing foil prepared in Step 2 is laid up in multiple layers according to process requirements to form a complex variable thickness brazing foil; the complex variable thickness brazing foil is connected to the lattice sandwich structure panel by micro-resistance spot welding process to achieve precise positioning of the brazing foil.

[0010] Step 4: Vacuum brazing is used to braze the positioned brazing filler metal to connect the core and the panel, thus preparing a lightweight, low-erosion-effect, and high-mechanical-performance lattice sandwich structure.

[0011] Preferably, the lattice sandwich structure is composed of a metal panel and a lattice core structure, and is formed by vacuum brazing. The vacuum brazing process uses amorphous foil as the brazing filler metal. The metal panel and the lattice core are made of titanium alloy or high-temperature alloy. The wall thickness of the lattice core is 0.02mm to 0.5mm, and the thickness of the metal panel is 0.8mm to 2.0mm. The lattice core is a three-dimensional periodic structure, which can be any one of four types: corrugated structure, honeycomb structure, pyramid structure, or complex core structure (honeycomb filled corrugated, honeycomb filled pyramid, etc.). The lattice core is a curved surface structure.

[0012] Preferably, it includes image acquisition, rapid image processing, and contour recognition;

[0013] The image recognition technology is a non-contact real-time measurement method, which avoids the problem of low measurement accuracy caused by the deformation of the dot matrix core during contact measurement, and is used to quickly detect the dot matrix core and generate a surface contour image.

[0014] The image recognition technology is applicable to surface measurement with discontinuous features, where the cross-section of the lattice core wall accounts for 5-70% of its total surface area.

[0015] Preferably, an industrial camera or a regular camera can be used;

[0016] The camera detection accuracy requirement is less than 0.01mm (or 12 megapixels);

[0017] Natural light or bottom lighting can be used;

[0018] No pretreatment such as surface coating is required for the dot matrix core;

[0019] No need to use gauge blocks, height gauges or other devices; just obtain a top view of the dot matrix core.

[0020] A grayscale conversion method is used to convert the color image of the dot matrix core top view into a black and white image, reducing subsequent processing time and storage space.

[0021] There is no need to identify individual cell nodes of the dot matrix core based on corner detection algorithms; only the overall image needs to be sharpened and black and white recognition performed.

[0022] The width of the solder strip needs to cover the entire lattice core wall. After cutting, the width of the solder strip should be 2 to 5 times the thickness of the lattice wall. The influence of the core burrs can be ignored, so there is no need to remove the burrs for measurement data.

[0023] Convert a color image to a black and white image;

[0024] Set the R, G, and B components of each pixel in the dot matrix image to be equal, i.e., R = G = B = V, where V is the gray value;

[0025] The grayscale value can be the maximum value among the three components R, G, and B, or the average value of the three components R, G, and B, or the weighted average value of the three components R, G, and B.

[0026] Grayscale value recognition is performed on a grayscale-converted black-and-white image.

[0027] Extract pixels with V values ​​in the range of 1 to 100, and determine whether the width of the area with the grayscale value meets the requirements is less than 2 to 5 times the pixel wall thickness.

[0028] If the thickness is less than 2 to 5 times the lattice wall thickness, the area should be leveled to remove sporadic noise.

[0029] If the V value is greater than 2 to 5 times the dot matrix wall thickness, the V value is further reduced, and the process is repeated until contour recognition is completed.

[0030] Preferably, the core contour parameters are imported into the control system, and ultrafast laser processing technology is used to achieve precise and non-destructive cutting of the brazing foil strip, avoiding excessive heat input from affecting the microstructure of the brazing foil strip;

[0031] The ultrafast laser processing technology described above uses picosecond or femtosecond laser light sources.

[0032] Preferably, the solder sheet is first fixed to the sample stage using a clamping device;

[0033] Then, the laser parameters of the picosecond laser are set as follows: the center wavelength of the picosecond laser is 1064nm, the repetition frequency is 250KHz, the single pulse energy is 200uJ@250kHz, the pulse width is 15ps, the laser output spot diameter is 1.2mm, the divergence angle is 2mrad, and the laser spot diameter after focusing by the galvanometer and field lens is 0.05mm.

[0034] Then input the laser-cut contour image parameters and motion trajectory into the processing software, set the processing trajectory parameters, where the laser trajectory movement speed is 1000mm / s and the number of processing times is 10.

[0035] Then, the processing software in the industrial control computer controls the picosecond laser to start emitting laser according to the laser parameters, and controls the two-dimensional galvanometer and XY moving platform to make the laser complete the precise cutting operation on the brazing foil strip along the predetermined movement trajectory.

[0036] Preferably, the solder sheet is first fixed to the sample stage using a clamping device;

[0037] Then, the laser parameters of the femtosecond laser were set: the center wavelength of the femtosecond laser was 1064nm, the repetition frequency was 200kHz, the single pulse energy was 100uJ@200kHz, the pulse width was 200fs, and the diameter of the laser spot after focusing by the galvanometer and field lens was 0.05mm.

[0038] Then input the contour image parameters of the laser cutting into the processing software, set the processing trajectory parameters, where the laser trajectory movement speed is 1000mm / s and the number of processing times is 15.

[0039] Then, the processing software in the industrial control computer controls the picosecond laser to start emitting laser according to the laser parameters, and controls the two-dimensional galvanometer and XY moving platform to make the laser complete the precise cutting operation on the brazing foil strip along the predetermined movement trajectory.

[0040] Preferably, the solder foil is composed of multiple layers of amorphous solder foil, and has the characteristics of complex geometry and variable thickness;

[0041] The solder foil strip has a similar shape to the lattice core, and the width of the solder foil strip slot should be 2 to 5 times the wall thickness of the lattice core.

[0042] Equal thickness brazing foil is suitable for welding planar and large curvature cores, while variable thickness brazing foil is suitable for welding small curvature and complex curved cores. This ensures that the brazing filler between the panel and the dot matrix core can fill the gap well, preventing poor brazing corner formation due to insufficient brazing filler and preventing the base material from being eroded or even sticking to the fixture due to excessive brazing filler.

[0043] The high-temperature alloy panel and core are welded together using nickel-based amorphous foil.

[0044] The titanium alloy panel and the core are welded together using titanium-based amorphous foil.

[0045] The thickness of the amorphous foil is 0.05 to 0.10 mm.

[0046] Preferably, the prepared amorphous brazing foil is laid up in multiple layers according to process requirements and connected by micro-resistance spot welding to form a complex variable thickness brazing foil.

[0047] Micro-resistance spot welding technology is used to connect complex variable thickness brazing foil strips to the dot matrix sandwich structure panel, achieving precise positioning of the brazing foil strips and preventing them from moving or misaligning in subsequent processes.

[0048] Preferably, a medium-frequency or high-frequency inverter current is used, and inert gas is used for rapid cooling; the key process parameters are welding current, welding time, electrode pressure, and electrode head size.

[0049] The welding current is 100-1500A; preferably 300-1000A, more preferably 500-800A;

[0050] The welding time is 2–20 ms; preferably 3–10 ms, more preferably 5–8 ms;

[0051] The electrode pressure is 10–200 N; preferably 40–100 N, more preferably 60–80 N;

[0052] The electrode size is 1-10 mm, preferably 2-8 mm, and more preferably 3-5 mm.

[0053] The beneficial effects of this invention are as follows:

[0054] 1. It can effectively prepare complex variable thickness brazing foil strips, so that the brazing filler between the panel and the lattice core can fill the gap between the brazing seams well, avoid poor brazing corner formation due to insufficient brazing filler, and prevent problems such as base material corrosion and adhesion of fixtures due to excessive brazing filler, thus achieving high-quality connection of metal lattice sandwich structure.

[0055] 2. For thinned dot matrix sandwich structure panels, the problem of excessive weight gain from the entire solder strip being detrimental to extreme lightweight requirements is avoided. By precisely cutting and positioning the solder foil strip, the weight gain of the solder is reduced while ensuring welding quality, thus meeting lightweight requirements.

[0056] 3. Image recognition technology is a non-contact real-time measurement method, which avoids the problem of low measurement accuracy caused by the deformation of the dot matrix core during contact measurement. It can quickly detect the dot matrix core and generate surface contour images, providing accurate parameters for subsequent precise cutting.

[0057] 4. Ultrafast laser cutting technology enables precise and non-destructive cutting of the solder foil, avoiding excessive heat input that could affect the microstructure of the solder and ensuring its performance. Micro-resistance spot welding connects the complex, variable-thickness solder foil to the lattice sandwich structure panel, achieving precise positioning of the solder foil and preventing misalignment in subsequent processes. Attached Figure Description

[0058] Figure 1 This is a flowchart of the present invention.

[0059] Figure 2 This is a contour diagram of the core of the present invention.

[0060] Figure 3 This is a laser processing path diagram of the present invention.

[0061] Figure 4 This is a table of process parameters for micro-resistance spot welding of the brazing filler strip of the present invention.

[0062] Figure 5 This is a time-temperature curve of the vacuum brazing process of the present invention. Detailed Implementation

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0066] Reference Figure 1-5 This paper presents a method for cutting and positioning brazing filler foil using a vacuum brazing process. The method aims to address the technical problems of poor local brazing quality and increased filler weight that reduces the lightweight nature of sandwich structures during vacuum brazing. Through image recognition, ultrafast laser cutting, multi-layer amorphous filler foil placement, micro-resistance spot welding, and vacuum brazing, this method achieves the fabrication of lightweight lattice sandwich structures with minimal erosion effects and excellent mechanical properties.

[0067] Image recognition

[0068] Image acquisition: Industrial or ordinary cameras can be used for image acquisition. The camera detection accuracy requirement is less than 0.01mm (or 12 megapixels), and natural light or bottom lighting can be used. No pre-processing such as surface coating of the dot matrix core is required, nor is it necessary to use gauge blocks, height gauges, or other devices; only a top view of the dot matrix core needs to be obtained.

[0069] Fast image processing: A grayscale conversion method is used to convert the color image of the dot matrix core top view into a black and white image, reducing subsequent processing time and storage space. There is no need to identify individual cell nodes of the dot matrix core based on corner detection algorithms; only overall image sharpening is required for black and white recognition.

[0070] Contour recognition: Grayscale value recognition is performed on the grayscale-converted black and white image. First, pixels with a V value between 1 and 100 are extracted. It is then determined whether the width of the region meeting the grayscale value requirement is less than 2 to 5 times the pixel wall thickness. If it is less, the region is flattened to remove sporadic noise; if it is greater, the V value is further reduced, and the process is repeated until contour recognition is complete.

[0071] Ultrafast laser cutting

[0072] Technical principle: Ultrafast laser processing technology uses picosecond or femtosecond laser light sources. Due to their extremely short pulses, energy is injected in a very short time, and heat cannot be dissipated, which will not cause chemical reactions such as thermal oxidation of materials, thus ensuring material performance and processing quality, and has a "cold processing" effect.

[0073] Picosecond laser cutting process:

[0074] The brazing filler metal sheet is fixed to the sample stage using a clamping device to ensure its stability during the cutting process.

[0075] The laser parameters of the picosecond laser are set as follows: center wavelength of 1064nm, repetition rate of 250kHz, single pulse energy of 200uJ@250kHz, pulse width of 15ps, laser output spot diameter of 1.2mm, divergence angle of 2mrad, and laser spot diameter of 0.05mm after focusing by the galvanometer field lens.

[0076] Input the contour image parameters and motion trajectory of the laser cutting into the processing software, set the processing trajectory parameters, where the laser trajectory movement speed is 1000mm / s and the number of processing times is 10.

[0077] The picosecond laser is activated by the processing software in the industrial control computer according to the laser parameters. The software also controls the two-dimensional galvanometer and the XY moving platform to make the laser follow the predetermined trajectory to complete the precise cutting operation on the brazing foil.

[0078] Femtosecond laser cutting process:

[0079] Similarly, the solder sheet is fixed to the sample stage using a clamping device.

[0080] The laser parameters of the femtosecond laser are set as follows: center wavelength of 1064nm, repetition rate of 200kHz, single pulse energy of 100uJ@200kHz, pulse width of 200fs, and laser spot diameter of 0.05mm after focusing by the galvanometer and field lens.

[0081] Input the contour image parameters and motion trajectory of the laser cutting into the processing software, set the processing trajectory parameters, where the laser trajectory movement speed is 1000mm / s and the number of processing times is 15.

[0082] The picosecond laser is activated by the processing software in the industrial control computer according to the laser parameters. The software also controls the two-dimensional galvanometer and the XY moving platform to make the laser follow the predetermined trajectory to complete the precise cutting operation on the brazing foil.

[0083] Multilayer amorphous solder strip installation and micro-resistance spot welding process

[0084] Multi-layer amorphous solder strip installation: The solder foil strip consists of multiple layers of amorphous solder foil strips, characterized by complex geometry and variable thickness. Multiple layers of amorphous solder strips are laid out according to process requirements to form complex, variable-thickness solder foil strips. The solder foil strip has a similar shape to the lattice core, and the width of the solder foil strip seam should be 2 to 5 times the wall thickness of the lattice core. Equal-thickness solder foil strips are suitable for welding planar and high-curvature cores, while variable-thickness solder foil strips are suitable for welding low-curvature and complex curved surface cores. This ensures that the solder fills the gap between the panel and the lattice core well, preventing poor solder joint formation due to insufficient solder and avoiding base material corrosion or even adhesion to the fixture due to excessive solder.

[0085] Micro-resistance spot welding process:

[0086] Medium-frequency or high-frequency inverter current is used, along with rapid cooling by inert gas. This improves welding efficiency and quality while preventing oxidation of the weld joint at high temperatures.

[0087] Key process parameters include welding current, welding time, electrode pressure, and electrode tip size. The welding current is 100–1500A, preferably 300–1000A, more preferably 500–800A; the welding time is 2–20ms, preferably 3–10ms, more preferably 5–8ms; the electrode pressure is 10–200N, preferably 40–100N, more preferably 60–80N; and the electrode size is 1–10mm, preferably 2–8mm, more preferably 3–5mm. By properly controlling these parameters, high-quality welded joints can be achieved, ensuring a strong and reliable connection between the brazing foil and the lattice sandwich structure panel.

[0088] By connecting the complex variable thickness solder foil strip to the dot matrix sandwich structure panel, the solder foil strip can be accurately positioned, avoiding movement or misalignment of the solder foil strip in subsequent processes.

[0089] Vacuum brazing

[0090] Vacuum brazing is used to braze the core and the panel with the positioned brazing filler metal to prepare a lightweight lattice sandwich structure with low erosion effect and good mechanical properties.

[0091] Advantages of Ultrafast Laser Cutting Technology

[0092] High precision: The small diameter of the laser spot enables high-precision cutting, meeting the cutting requirements of brazing foil strips with complex shapes and sizes.

[0093] Non-destructive cutting: The "cold working" effect avoids the impact of excessive heat input on the microstructure of the brazing filler band, ensuring the performance and quality of the brazing filler.

[0094] High flexibility: The laser cutting parameters and trajectory can be flexibly adjusted according to the shape and size of different dot matrix sandwich core structures to achieve personalized cutting solutions.

[0095] High efficiency: Laser cutting is fast, which can improve production efficiency and reduce production costs.

[0096] Advantages of micro-resistance spot welding process

[0097] Precise positioning: Achieve precise positioning of the solder foil strip to avoid movement or misalignment in subsequent processes.

[0098] The connection is strong and reliable: the resulting metallurgical joint has high strength and reliability, which can meet the requirements of lattice sandwich structures in various harsh environments.

[0099] Highly adaptable: Suitable for welding workpieces of different materials and thicknesses, with strong adaptability and versatility.

[0100] High-efficiency production: Simple to operate, high production efficiency, and able to meet the needs of large-scale production.

[0101] In summary, this method provides an effective solution for high-quality connection of lattice sandwich structures through the synergistic effect of image recognition, ultrafast laser cutting, multi-layer amorphous brazing strip laying and micro-resistance spot welding process, and vacuum brazing.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cutting positioning method of a filler metal foil tape for a vacuum brazing process, characterized by: The method comprises the following steps: Step 1: image recognition is performed on the core of the dot matrix sandwich structure to generate a two-dimensional image of the surface profile of the core, including image acquisition, image rapid processing and profile recognition; Step 2: the core profile parameters generated in step 1 are imported into a control system, and superfast laser processing technology is used to realize precise and non-destructive cutting of the filler foil, so as to avoid excessive heat input affecting the microstructure of the filler foil; Step 3: the amorphous filler foil prepared in step 2 is laid according to the process requirements to form a complex variable-thickness filler foil; and a micro-resistance spot welding process is used to connect the complex variable-thickness filler foil with the dot matrix sandwich panel to realize precise positioning of the filler foil; Step 4: vacuum brazing is used to connect the core and the panel by brazing the positioned filler to prepare the dot matrix sandwich structure.

2. The cutting and positioning method of a brazing foil strip for a vacuum brazing process according to claim 1, characterized in that: The dot matrix sandwich structure is composed of a metal panel and a dot matrix core structure, and is formed by a vacuum brazing process, wherein the vacuum brazing process uses an amorphous foil as filler, and the metal panel and the dot matrix core material are titanium alloy or high-temperature alloy, the wall thickness of the dot matrix core is 0.02mm-0.5mm, the thickness of the metal panel is 0.8mm-2.0mm, and the dot matrix core is a three-dimensional periodic structure.

3. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 1, characterized in that: The image recognition includes image acquisition, image rapid processing and profile recognition; The image recognition technology is a non-contact real-time measurement method for quickly detecting the dot matrix core and generating a surface profile image; The image recognition technology is suitable for surface measurement of surfaces with discontinuous characteristics, and the proportion of the cross-section of the dot matrix core to the total surface area is 5-70%.

4. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 3, characterized in that: An industrial camera or a common camera is used; The camera detection accuracy is required to be less than 0.01mm; Natural light or bottom light is used; An overhead view of the dot matrix core is obtained; A grayscale processing method is used to convert the color image of the overhead view of the dot matrix core into a black and white image, thereby reducing the subsequent processing time and storage space; The overall image is sharpened and black and white recognition is performed; The width of the filler strip needs to cover the entire dot matrix core wall, and the width of the filler strip after cutting should be 2-5 times the wall thickness of the dot matrix, so the influence of the core burr can be ignored, and therefore there is no need to remove the burr from the measured data; The color image is converted into a black and white image; The R, G and B components of each pixel point of the dot matrix core image are set to be equal, i.e. R=G=B=V, wherein V is the grayscale value; The grayscale value can be the maximum value of the R, G and B components or the average value of the R, G and B components or the weighted average value of the R, G and B components; The black and white image after grayscale processing is subjected to grayscale value recognition; The pixel points with V values in the range of 1-100 are extracted, and it is judged whether the width of the region with the grayscale value meeting the requirements is less than 2-5 times the wall thickness of the dot matrix; If it is less than 2-5 times the wall thickness of the dot matrix, the region is subjected to flattening treatment to remove sporadic noise points; If it is greater than 2-5 times the wall thickness of the dot matrix, the V value is further reduced, and the process is repeated until the profile recognition is completed.

5. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 1, characterized in that: The core profile parameters are imported into a control system, and superfast laser processing technology is used to realize precise and non-destructive cutting of the filler foil, so as to avoid excessive heat input affecting the microstructure of the filler foil; The superfast laser processing technology uses a picosecond or femtosecond laser light source.

6. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 5, characterized in that: the brazing foil strip is first fixed on the sample table by the clamping device; then the laser parameters of the picosecond laser are set, the center wavelength of the picosecond laser is 1064 nm, the repetition frequency is 250 KHz, the single pulse energy is 200 uJ@250 kHz, the pulse width is 15 ps, the laser spot diameter of the laser is 1.2 mm, the divergence angle is 2 mrad, and the laser spot diameter after focusing of the galvanometer field lens is 0.05 mm; then the profile image parameters of the laser cutting are input into the processing software, and the processing track parameters are set, wherein the laser track movement speed is 1000 mm / s, and the processing times is 10; then the picosecond laser is started to emit laser according to the laser parameters by the processing software in the industrial computer, and the two-dimensional galvanometer and the XY moving platform are controlled, so that the laser completes the precise cutting operation on the brazing foil strip along the predetermined action track.

7. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 5, characterized in that: the brazing foil strip is first fixed on the sample table by the clamping device; then the laser parameters of the femtosecond laser are set, the center wavelength of the femtosecond laser is 1064 nm, the repetition frequency is 200 KHz, the single pulse energy is 100 uJ@200 kHz, the pulse width is 200 fs, and the laser spot diameter after focusing of the galvanometer field lens is 0.05 mm; then the profile image parameters of the laser cutting are input into the processing software, and the processing track parameters are set, wherein the laser track movement speed is 1000 mm / s, and the processing times is 15; then the picosecond laser is started to emit laser according to the laser parameters by the processing software in the industrial computer, and the two-dimensional galvanometer and the XY moving platform are controlled, so that the laser completes the precise cutting operation on the brazing foil strip along the predetermined action track.

8. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 1, characterized in that: the brazing foil strip is composed of multiple layers of amorphous brazing foil strips, and has the characteristics of complex geometric shape and variable thickness; the brazing foil strip has a similar shape to the dot matrix core, and the brazing foil strip seam width should be 2-5 times the wall thickness of the dot matrix core; the equal-thickness brazing foil strip is suitable for planar and large-curvature core welding, and the variable-thickness brazing foil strip is suitable for small-curvature and complex curved surface core welding, so that the brazing filler metal between the panel and the dot matrix core can be well filled in the gap, neither the brazing angle forming is not good due to insufficient brazing filler metal, nor the base material is dissolved or even adhered to the clamp due to excessive brazing filler metal; the high-temperature alloy panel and the core are welded by using nickel-based amorphous foil; the titanium alloy panel and the core are welded by using titanium-based amorphous foil; the thickness of the amorphous foil is 0.05-0.10 mm.

9. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 8, characterized in that: The prepared amorphous brazing foil strip is laid according to the process requirements, and connected by micro-resistance spot welding process to form a complex variable-thickness brazing foil strip. The complex variable-thickness filler metal foil is connected with the dot matrix sandwich structure panel by micro-resistance spot welding process, so as to realize accurate positioning of the filler metal foil and avoid displacement of the filler metal foil in subsequent processes.

10. The cutting and positioning method of the brazing foil strip for the vacuum brazing process according to claim 9, characterized in that: Adopting intermediate frequency or high frequency inverter current, inert gas is cooled at a very high speed; The welding current is 100-1500 A; The welding time is 2-20 ms; The electrode pressure is 10-200 N; The electrode size is 1-10 mm.

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